That's exactly what I thought. And I do think that the oxygen sensor might be causing (at least some) of the problem. I tried out some troubleshooting (as outlined in the Bentley manual-taking meter readings at the connector for the ECU. The pin connecting from oxygen sensor to ground did not produc...

My 1990 Volvo 240 Sedan has approx. 240k miles on it. For a while now it has been consuming fuel at a high rate. The ECU had fault code readout 232 (faulty fuel injectors) and 113 (fuel system compensating for rich air/fuel mix). It also puffs out small amounts of black exhaust. A trusted and reliab...